Emerson / Motorola MVME335 4-Channel Serial and Parallel Interface Board

The Emerson/Motorola MVME335 is a 6U VMEbus interface board that provides four channels of serial communication and parallel connectivity for industrial automation, data acquisition, and control systems. Built around a Motorola PowerPC MPC860 processor running at 50–100 MHz, the board delivers real-time processing capabilities with up to 32 MB DRAM and on-board Flash memory. Two RS-232/RS-422/RS-485 serial ports and one Centronics-compatible parallel interface enable direct connection to legacy and modern peripherals. An integrated 10Base-T Ethernet port supports network integration without external adapters.

## Technical Specifications

• **Processor:** Motorola PowerPC MPC860, 50–100 MHz
• **Memory:** Up to 32 MB DRAM (expandable), on-board Flash for OS and applications
• **Serial Interfaces:** 2 × RS-232/RS-422/RS-485 ports
• **Parallel Interface:** 1 × Centronics-compatible port (optional)
• **Ethernet:** 10Base-T port
• **Power Consumption:** 8–15 W from +5V (±5%) supply
• **Operating Temperature:** 0°C to +60°C
• **Form Factor:** 6U Eurocard (233.35 × 160 mm)

## Key Features

• VMEbus Master/Slave operation with full address and data width support (A16, A24, A32; D8, D16, D32)
• Block transfer modes: MBLT64 and 2eSST for high-speed data movement
• System Controller functions including bus arbitration, interrupt acknowledgment (IACK), system clock (SYSCLK), and bus timer
• 4-level requester, 7-level interrupter, and 7-level interrupt handler architecture
• VME64 extension connector with backward compatibility to existing VMEbus systems

## Typical Applications

• Industrial control and real-time automation systems
• Data acquisition and instrumentation platforms
• Legacy VMEbus system modernization with serial device support
• Distributed I/O and sensor integration in embedded environments

## Compatibility & Integration

The MVME335 integrates directly into VMEbus-based systems and maintains full compatibility with VME64 specifications. The board functions as a System Controller, managing bus arbitration and interrupt handling across the VME backplane, making it suitable for multi-card real-time processing architectures.